A spectrometer system includes an array of micro-zone plates (MZP) each having coaxially-aligned ring gratings, a sample plate for supporting and illuminating a sample, and an array of photon detectors for measuring a spectral characteristic of the predetermined wavelength. The sample plate emits an evanescent wave in response to incident light, which excites molecules of the sample to thereby cause an emission of secondary photons. A method of detecting the intensity of a selected wavelength of incident light includes directing the incident light onto an array of MZP, diffracting a selected wavelength of the incident light onto a target focal point using the array of MZP, and detecting the intensity of the selected portion using an array of photon detectors. An electro-optic layer positioned adjacent to the array of MZP may be excited via an applied voltage to select the wavelength of the incident light.
|
5. An arrayed spectrometer system comprising:
an array of micro-zone plates (MZP) each having a plurality of coaxially-aligned ring gratings configured for diffracting a predetermined wavelength of incident light from a sample onto a target focal point;
a sample plate configured for supporting and illuminating the sample, wherein the sample plate defines a plurality of apertures adapted for passing a portion of source light to the sample as the incident light; and
an array of photon detectors each operable for measuring an intensity of the predetermined wavelength.
1. An arrayed spectrometer system comprising:
an array of microzone plates (MZP) each having a plurality of coaxially-aligned ring gratings configured for diffracting a predetermined wavelength of incident light from a sample onto a target focal point;
an electro-optic layer positioned adjacently to the array of MZP;
a sample plate configured for supporting the sample, and for passing a portion of source light to the sample to generate the incident light; and
an array of photon detectors, wherein each photon detector in the array of photon detectors is operable for detecting a spectral characteristic of the predetermined wavelength.
10. A method of detecting the intensity of a selected wavelength of incident light, the method comprising:
directing source light onto one side of a sample plate and through a plurality of apertures defined thereby to illuminate a sample positioned on the other side of the sample plate, wherein illumination of the sample generates the incident light;
directing the incident light onto an array of micro-zone plates (MZP), wherein each MZP in the array of MZP has a plurality of coaxially-aligned ring gratings configured for diffracting the selected wavelength of the incident light onto a target focal point;
diffracting the selected wavelength onto the target focal point using the array of MZP; and
detecting the intensity of the selected wavelength using an array of photon detectors.
2. The arrayed spectrometer system of
3. The arrayed spectrometer system of
4. The arrayed spectrometer system of
6. The arrayed spectrometer system of
7. The arrayed spectrometer system of
8. The arrayed spectrometer system of
9. The arrayed spectrometer system of
11. The method of
using a data recorder to record the detected intensity.
12. The method of
13. The method of
14. The method of
|
This application claims priority to and the benefit of U.S. Provisional Application 61/089,226 filed on Aug. 15, 2008, which is hereby incorporated by reference in its entirety.
The invention described herein was made by employees of the United States Government and may be manufactured and used by or for the Government for governmental purposes without payment of any royalties thereon or therefor.
The present invention relates generally to spectrometers, and in particular to spectrometers having an array of thin-film micro-zone plates (MZP) suitable for acquiring photons of a specific wavelength from one or more point light sources.
Spectroscopic analysis or spectroscopy pertains to the study of the dispersion of light into its component wavelengths. By analyzing the absorption and dispersion of incident light and other radiation by matter, scientists are able to study various properties of the matter such as temperature, mass, luminosity, composition, etc. Optical instruments known as spectrometers are used to measure and study such light dispersion. Spectrometers therefore play an essential role in the study and design of various scientific monitoring devices, for example multi-spectral imaging (MSI) systems, hyper-spectral imaging (HSI) systems, and the like.
In a conventional spectrometer, incident light passes through a first linear opening or slit in a mirror or an optical lens. A beam of incident light passing through the first slit illuminates a prism or a linear grating device. The grating device may have a series of vertically-aligned gratings which diffract the incident light into its component colors, with each color corresponding to a particular band of wavelengths of the electromagnetic spectrum.
Spectrometers may include multiple aperture slits, with the first slit positioned in front of the linear grating device to initially select light in a relatively narrow band of wavelengths. The linear grating device spreads this portion of the light beam at different wavelength-dependent angles. A second slit in another mirror or optical lens may be positioned to allow selective passage of a narrower band of the light beam from the linear grating device. The second slit may be used to direct selected wavelengths to a measurement device to determine a desired spectral characteristic. In this manner, a specific wavelength or set of wavelengths may be selected for detailed spectral analysis.
Conventional spectrometers as described above are often used to acquire and analyze light from a single point source, but may require additional lenses or mirrors to capture a point light source. Because a single spectrometer cannot make a two-dimensional (2D) image without scanning, the total speed of acquiring 2D spectral data is also relatively slow. For example, if it takes approximately 10 seconds to resolve a first spot, 1024×768 images will require 7,864,320 seconds or 91 days to complete. A multi-channel position-sensitive device or Charged Coupled Detector (CCD) array may eliminate the need for a linear aperture slit, but nevertheless may require the additional dimension in order to function properly. A red-green-blue (RGB) CCD array may be used to capture 2D images. However, the color filters of such CCD arrays may have less than optimal spectral resolution.
Accordingly, a miniature arrayed spectrometer system is provided herein that can be used to rapidly build a high-resolution two-dimensional (2D) image of desired spectral information or data while potentially providing significant size advantages relative to the designs of the prior art. Within the scope of the present invention, the spectrometer system uses an array of photon detectors in conjunction with an array of thin-film micro-ring gratings in the form of micro-zone plates (MZP). The MZP may be configured with an electro-optic layer that can be energized to optimize data acquisition times. The arrayed spectrometer system does not require the use of a focusing lens for micro-objects due to its multiple built-in optical focal points.
In particular, the arrayed spectrometer system includes a plurality of MZP, hereinafter referred to as an MZP array, with each MZP in the MZP array having a plurality of coaxially-aligned annular or ring-shaped gratings. Each MZP diffracts a selected wavelength of incident light from sample matter onto a target focal point, e.g., incident light from a micro/nano object. The spectrometer system also includes a sample layer configured for supporting and illuminating the sample via passage of light through a plurality of apertures, and an array of photon detectors for measuring a desired spectral characteristic of the selected wavelength, e.g., light intensity.
According to one embodiment, each MZP in the MZP array is configured as one of a positive MZP or a negative MZP as those terms are described herein. That is, each MZP in the MZP array is identically configured. An electro-optic layer may be energized to select a wavelength. A beam separator may be positioned adjacent to the MZP array to separate unwanted wavelengths of light from the desired or selected wavelengths.
The sample layer may be configured to emit an exponentially-decaying electrical field or an evanescent wave in response to the incident light, with the evanescent wave exciting molecules of the sample to thereby cause an emission of secondary photons from the sample. These photons are detectable using the array of photon detectors or detector array. A data recorder or other suitable recording device may be placed in communication with the detector array and used to record the intensity of the selected wavelengths or another desired spectral characteristic.
A method of detecting the intensity of selected wavelengths of incident light includes directing the incident light onto an MZP array, with each MZP having a plurality of coaxially-aligned annular or ring-shaped gratings. The gratings are configured for diffracting a predetermined wavelength of light from a sample onto a target focal point. The method includes directing source light onto one side of a sample plate and through a plurality of apertures defined thereby in order to illuminate a sample on the other side of the sample plate. Illumination of the sample generates the incident light, which passes to the MZP array. The MZP array diffracts the selected wavelength(s) onto the target focal point. The method includes detecting the intensity of the selected wavelength(s) using an array of photon detectors.
The above features and advantages and other features and advantages of the present invention are readily apparent from the following detailed description of the best modes for carrying out the invention when taken in connection with the accompanying drawings.
Referring to the drawings wherein like reference numbers represent like components throughout the several figures, and beginning with
The positive MAP 10 includes a transparent center disk 12 that is circumscribed by a series of progressively larger transparent rings 14. The transparent rings 14 are separated by an interposed series of progressively larger opaque rings 16, with the center disk 12 and each of the rings being coaxially-aligned and centered on a common optical axis 11. For simplicity, the number of rings is kept at a minimum in
The transparent center disk 12 and the various rings 14, 16 may be configured as optical gratings on thin film. As will be understood by those of ordinary skill in the art, the term “optical gratings” refers to an optical element configured for diffracting incident light and directing it to a predetermined optical focal point. Gratings have a regular pattern which split and diffract incident light into several beams travelling in directions that depend on the spacing between gratings and the wavelength of the incident light.
Source light (arrows 13) is directed toward the MZP 10 from a source, e.g., a micro/nano object, organism, matter, or other substance serving as the subject of the spectral analysis at hand. The source light is then diffracted by the various rings 14, 16 of the MZP 10 into different wavelengths, with each wavelength directed toward a particular focal point P1, P2, P3, P4, or P5. That is, the particular focal point corresponds to particular wavelengths or frequencies of the source light (arrows 13). The transparent center disk 12 allows a constructive interference point at the farthest focal point, i.e., focal point P1. Additional constructive interference points are provided at focal points P3 and P5.
As is well understood in the art, the transmission of light in the form of waves gives rise to the principals of constructive and destructive wave interference. During any wave interference the shape of the medium is determined by the sum of the separate amplitudes of each wave. The waves interfere when one wave passes through another. When the crest of one wave is superpositioned upon the crest of another, the waves constructively interfere. Constructive interference also occurs when the trough of one wave is superpositioned upon the trough of another. Conversely, destructive interference occurs when the crest of one wave is superpositioned upon the trough of another. During destructive interference, the positive amplitudes from one crest are added to the negative amplitudes from the other trough, with the result being a reduced amplitude or destructive wave interference. Such principles give rise to the different constructive/destructive focal points discussed above.
Referring to
The MZP 10, 10A may be used as micro-ring gratings that focus parallel photons of source light (arrows 13) into the different radial points according to their wavelengths. A photon detector (D) 18 may be placed at any of the focal points P1-P5, and may relay or transmit detected information (arrow i) to a data recorder (R) 20 to provide a historical record for facilitation of spectral analysis. 0th order direct photons from the source light (arrows 13) through the transparent center disk 12 of
This result is similar to the Fourier transform in which y=c (a constant) is approximated by the sum of infinite sine and cosine waves. However, a negative MAP such as the MAP 10A of
Referring to
For a positive MZP 10 (see
Referring to
Referring to
When backside light (arrow 19) is incident on the sample plate 30 at a glancing angle, total internal reflection occurs so that no photon is able to travel above surface 32. Exit light (arrow 25) is reflected away from the sample plate 30. However, the tangential component of the electric field ({right arrow over (E)}) is still continuous above the surface 32, and this tangential component decays exponentially with time (t) above the surface 32 as shown in the superimposed graph 36 plotting Z vs. {right arrow over (E)}1.
This vertically-decaying time-varying electric field is known as the evanescent wave. Because the evanescent wave is decaying quickly along the Z-axis, it cannot reach the photon detector 18 (see
Referring to
Referring to
The detector array 122 receives light of a specific wavelength from each MZP 10 in the MZP array 40. For a fixed-ring grating MZP, the distance or focal length Z between the plane of the sample plate 30 and the MZP array 40 may be changed to select a different wavelength of light for spectral analysis. As shown in
While acquisition of point-source light is noted above, those of ordinary skill in the art will readily appreciate that the arrayed spectrometer system 50 can also acquire light from greater distances. That is, each aperture 34 can confine parallel light transmitted over a distance and effectively convert the light to an equivalent point-source. In this manner the system 50 can be used to capture 2D spectral data from far objects, thus enabling a host of potential applications including but not limited to multi-spectral imaging (MSI), hyper-spectral imaging (HSI), and other remote sensing and/or spectral analysis applications.
While the best modes for carrying out the invention have been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention within the scope of the appended claims.
Park, Yeonjoon, Elliott, James R., King, Glen C., Choi, Sang H.
Patent | Priority | Assignee | Title |
10514296, | Jul 29 2015 | Samsung Electronics Co., Ltd.; California Institute of Technology | Spectrometer including metasurface |
10739198, | Dec 16 2016 | Fraunhofer-Gesellschaft zur Foerderung der Angewandten Forschung E V | System for analyzing electromagnetic radiation, and device for producing same |
11162841, | Jul 29 2015 | Samsung Electronics Co., Ltd.; California Institute of Technology | Spectrometer including metasurface |
11268854, | Jul 29 2015 | SAMSUNG ELECTRONICS CO , LTD ; California Institute of Technology | Spectrometer including metasurface |
11867556, | Jul 29 2015 | Samsung Electronics Co., Ltd.; California Institute of Technology | Spectrometer including metasurface |
9420666, | Jan 03 2011 | LEDMOTIVE TECHNOLOGIES, S L | Optoelectronic device, system and method for obtaining an ambient light spectrum and modifying an emitted light |
Patent | Priority | Assignee | Title |
3107270, | |||
3454338, | |||
3603685, | |||
3649837, | |||
4429411, | Apr 20 1981 | The United States of America as represented by the United States | Instrument and method for focusing X-rays, gamma rays and neutrons |
4572616, | Aug 10 1982 | SYRACUSE UNIVERSITY, A CORP OF N Y | Adaptive liquid crystal lens |
4743083, | Dec 30 1985 | Cylindrical diffraction grating couplers and distributed feedback resonators for guided wave devices | |
4752130, | Oct 24 1986 | The University of Rochester | Optical systems utilizing a volume transmission diffraction element to provide wavelength tuning |
4775967, | Oct 11 1984 | Hitachi, Ltd. | Beam spot control device using a thin micro lens with an actuator |
4822148, | Sep 23 1987 | Eastman Kodak Company | Multicolor light valve imaging apparatus having electrode constructions for uniform transmission |
4909626, | Jul 28 1986 | The General Electric Company, p.l.c. | Electrically-controllable thin film Fresnel zone device |
4995714, | Aug 26 1988 | CooperVision International Holding Company, LP | Multifocal optical device with novel phase zone plate and method for making |
5011284, | Mar 22 1990 | KAISER OPTICAL SYSTEMS, INC A CORP OF MICHIGAN | Detection system for Raman scattering employing holographic diffraction |
5071253, | Dec 26 1985 | OMEGA TECH, INC , CORP OF MD | Optical light beam position control system |
5121378, | Jun 14 1988 | NEC Corporation | Optical head apparatus for focussing a minute light beam spot on a recording medium |
5204516, | Apr 23 1991 | U.S. Philips Corporation | Planar optical scanning head having deficiency-correcting grating |
5268973, | Jan 21 1992 | Board of Regents, The University of Texas System | Wafer-scale optical bus |
5357591, | Apr 06 1993 | Cylindrical-wave controlling, generating and guiding devices | |
5360973, | Feb 22 1990 | Raytheon Company | Millimeter wave beam deflector |
5731874, | Jan 24 1995 | The Board of Trustees of the Leland Stanford Junior University | Discrete wavelength spectrometer |
5793488, | Jul 31 1995 | Tropel Corporation | Interferometer with compound optics for measuring cylindrical objects at oblique incidence |
5986758, | Aug 18 1998 | United States Air Force | Diffractive optic image spectrometer (DOIS) |
5995221, | Feb 28 1997 | HORIBA INSTRUMENTS INCORPORATED | Modified concentric spectrograph |
6167016, | Apr 11 1997 | MARBURG TECHNOLOGIES, INC | Optical head with a diffractive lens for focusing a laser beam |
6226083, | May 05 1999 | Georgia Tech Research Corporation | Integrated-optic spectrometer and method |
6269066, | Jul 24 1997 | SCULLY, RICHARD L | Electronically translocatable optical stylet |
6335625, | Feb 22 1999 | PICO TECHNOLOGY HOLDINGS, INC | Programmable active microwave ultrafine resonance spectrometer (PAMURS) method and systems |
6366547, | Mar 06 1998 | SCULLY, RICHARD L | Ultra high density disk reader/writer comprising two interferometers |
6452675, | Mar 19 1998 | Thin-film spectrometer with transmission grid | |
6509559, | Jun 20 2000 | ISMECA SEMICONDUCTOR HOLDING SA | Binary optical grating and method for generating a moire pattern for 3D imaging |
6518555, | Mar 20 1998 | Pioneer Electronic Corporation | Polarization hologram lens, optical pickup, information reproduction apparatus and information recording apparatus |
6583873, | Sep 25 2000 | The Carnegie Institution of Washington | Optical devices having a wavelength-tunable dispersion assembly that has a volume dispersive diffraction grating |
6597452, | Nov 17 2000 | HORIBA INSTRUMENTS INCORPORATED | Compact littrow-type scanning spectrometer |
6643065, | Jan 18 2001 | CHARTOLEAUX KG LIMITED LIABILITY COMPANY | Variable spacing diffraction grating |
6762839, | Dec 04 1996 | Research Foundation of City College of New York | System and method for performing selected optical measurements utilizing a position changeable aperture |
6777656, | Sep 28 2001 | JASCO Corporation | Near-field spectrometer having background spectral information |
6785201, | Jun 21 2002 | Seiko Instruments Inc; OHKUBO, TOSHIFUMI; HIROTA, TERUNAO; ITAO, KIYOSHI | Optical information recording and reading apparatus |
6847447, | Mar 13 2000 | FPS FOOD PROCESSING SYSTEMS B V | Apparatus and method and techniques for measuring and correlating characteristics of fruit with visible/near infra-red spectrum |
6856406, | Mar 06 1998 | Richard L., Scully | Ultra small spot generator |
6947453, | Jan 17 2002 | Optitune plc | Tunable diffractive device |
6995840, | Mar 06 2002 | MUDLOGGING SYSTEMS INC | Method and apparatus for radiation encoding and analysis |
6999165, | Jun 26 1998 | MUDLOGGING SYSTEMS INC | Method and apparatus for radiation analysis and encoder |
7072442, | Nov 20 2002 | KLA-Tencor Technologies Corporation | X-ray metrology using a transmissive x-ray optical element |
7084972, | Jul 18 2003 | Chemimage Technologies LLC | Method and apparatus for compact dispersive imaging spectrometer |
7106664, | Nov 13 2002 | Fujitsu Limited | Optical head and information storage device |
7158228, | Jul 25 2002 | California Institute of Technology; Massachusetts Institute of Technology | Holographic imaging spectrometer |
7161673, | Mar 02 2001 | ALCON REFRACTIVEHORIZONS, INC | Spectrometer comprising active matrix optics |
7196791, | Nov 30 2000 | Tomra Systems ASA | Optical detection device |
7253958, | Jul 31 2003 | Lucent Technologies Inc. | Tunable micro-lens arrays |
7262917, | Feb 13 2004 | Board of Supervisors of Louisiana State University and Agricultural and Mechanical College | Out-of-plane pre-aligned refractive micro lens |
7576855, | May 19 2005 | Shimadzu Corporation | Spectrophotometric method and apparatus |
7630287, | Jan 26 2000 | Seiko Instruments Inc. | Near field optical head and optical recording device |
7872959, | Oct 12 2001 | Konica Corporation | Objective lens, optical element, optical pick-up apparatus and optical information recording and/or reproducing apparatus equipped therewith |
20010046276, | |||
20040032585, | |||
20040175174, | |||
20070109924, | |||
20070164842, | |||
20070165221, | |||
20080020480, | |||
20080094631, | |||
20080119060, | |||
20090161520, |
Date | Maintenance Fee Events |
Sep 23 2015 | M1551: Payment of Maintenance Fee, 4th Year, Large Entity. |
Dec 30 2019 | REM: Maintenance Fee Reminder Mailed. |
Jun 15 2020 | EXP: Patent Expired for Failure to Pay Maintenance Fees. |
Date | Maintenance Schedule |
May 08 2015 | 4 years fee payment window open |
Nov 08 2015 | 6 months grace period start (w surcharge) |
May 08 2016 | patent expiry (for year 4) |
May 08 2018 | 2 years to revive unintentionally abandoned end. (for year 4) |
May 08 2019 | 8 years fee payment window open |
Nov 08 2019 | 6 months grace period start (w surcharge) |
May 08 2020 | patent expiry (for year 8) |
May 08 2022 | 2 years to revive unintentionally abandoned end. (for year 8) |
May 08 2023 | 12 years fee payment window open |
Nov 08 2023 | 6 months grace period start (w surcharge) |
May 08 2024 | patent expiry (for year 12) |
May 08 2026 | 2 years to revive unintentionally abandoned end. (for year 12) |